char grade='B';

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
    switch (grade){
      case 'A':
        Serial.println("Excellent");
      break;
    
      case 'B':
        Serial.println("Best");
      break;
      
      case 'C':
        Serial.println("Good");
      break;

      default:
        Serial.println("No match");
      break;
  }
    delay(1500);
}